US authorities sued the entrepreneur for misleading investors and he and Tesla were each fined $20m. Mr Musk was also obliged to relinquish his role as chairman for three years.

Investors had also called for stronger oversight of Mr Musk after his erratic behaviour attracted attention. In media interviews he said he often slept on a sofa in the Tesla office and more recently in an online video he briefly smoked marijuana.

Tesla, which has never reported an annual profit, also came under strain over production schedules for its Model 3 electric car, its newest car aimed at a wider market. However, the carmaker made what Mr Musk called an "historic" profit in the most recent quarter.

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Ms Denholm, who has been on Tesla's board since August 2014, became Telstra CFO in July.

She will take on the full-time role at Tesla after serving a six-month notice period at the Australian firm.

"I believe in this company, I believe in its mission and I look forward to helping Elon and the Tesla team achieve sustainable profitability and drive long-term shareholder value," Ms Denholm said.

Before moving to Telstra, she worked for Silicon Valley firms Sun Microsystems and Juniper Networks as well as consultants Arthur Anderson and Toyota.

"Robyn has extensive experience in both the tech and auto industries, and she has made significant contributions as a Tesla board member over the past four years in helping us become a profitable company," said Mr Musk.